Method of indicating the level of a molten fluid

ABSTRACT

A method of indicating a predetermined level of a molten fluid contained in an ingot-forming member for forming the molten fluid into an ingot when it cools is disclosed. The ingot-forming member has a molten fluid receiving end, an inner wall, an outer wall and a top wall bridging the inner wall and the outer wall. The method includes the steps of: (a) providing a support member in loose fitting engagement with the ingot-forming member and having an outside support portion adjacent the outer wall, an inside support portion adjacent the inner wall and a bridging support portion adjacent the top wall for connecting the outside support portion and the inside support portion; and (b) mounting a float member on the free end of the inside support portion to extend inwardly from the inner wall at the predetermined level substantially parallel to the level of the fluid line of the molten fluid. The float member has a molten fluid contact volume so that the mean density of the sum of the weights of the support member and the float member per unit of volume of the contact volume is less than the mean density of the molten fluid and so that when the molten fluid engages the float member the support member moves away from the top wall of the ingot-forming member thereby giving a visual signal of the molten fluid reaching the predetermined level. The float member is formed of a material having an ignition temperature lower than the temperature of the molten fluid so that the float member is partially consumed upon contact with the molten fluid thereby decreasing the weight of the indicating device and produces downward flowing gases from the float member against the molten fluid to aid in the elevation of the float member thereby speeding up the visual signal.

O Umted States Patent 1151 3,643,724

Lee Feb. 22, 1972 [54] METHOD OF INDICATING THE LEVEL fluid into an ingot when it cools is disclosed. The ingot-form- OF A MOLTEN FLUID ing member has a molten fluid receiving end, an inner wall, an outer wall and a top wall bridging the inner wall and the outer Inventor: veme Portage wall. The method includes the steps of: (a) providing a sup- [73] Assisnee: United States sted Corporation port member in loose fitting engagement with the ingot-forming member and having an outside support portion adjacent Filedi 1970 the outer wall, an inside support portionadjacent the inner [21] Appl No; 22,968 wall and a bridging support portion adjacent the top wall for connectmg the outslde support portlon and the 1ns|de support portion; and (b) mounting a float member on the free end of [52] [1.8. CI ..l64/4, 1 16/1 18, 164/150, the inside support portion to extend inwardly from the inner 249/202 wall at the predetennined level substantially parallel to the [51] Int. Cl. ..B22c 19/04, G01f 23/06 level of the fluid line of the molten fluid. The float member has [58] Field of Search ..249/202, 197-201, a molten fluid contact volume so that the mean density of the /1 /1 4; 116/ 1 1 ,11 108/46 sum of the weights of the support member and the float member per unit of volume of the contact volume is less than 1 References Cit d the mean density of the molten fluid and so that when the molten fluid en a es the float member the support member moves UNITED STATES PATENTS away from ihg top wall of the ingot-forming member thereby 409,339 8/1889 Stuyvesant ..1 16/1 18 giving a visual signal of the molten fluid reaching the predeter- 42 737 3/ 922 Spencer n 103 4 X mined level. The float member is formed of a material having 3,236,492 2/1966 Wetzig ..249/202 an ignition temperature lewer than the temperature of the Primary ExaminerRobert D. Baldwin Attomey-Robert J. Leek, Jr.

[57] ABSTRACT A method of indicating a predetermined level of a molten fluid molten fluid so that the float member is partially consumed upon contact with the molten fluid thereby decreasing the weight of the indicating device and produces downward flowing gases from the float member against the molten fluid to aid in the elevation of the float member thereby speedingup the visual signal.

contained in an ingot-forming member for forming the molten 4 Claims, 9 Drawing Figures I2 26 I I6 24 34 1 l t f f 42 1 l l 2a 1 1 /5 30 3a B 8 -22 dk 0 fil I l lsa l5a- PAIENTEUFEB 22 I972 SHEET 1 OF 3 lNl/E/VTOR VER/VE E. LEE

AI/orne PATENTEDFEBZZ I972 3, 643 724 sum 2 BF 3 INVENTOR l/ER/VE E. LEE

y Afro ey PATENTEDFEB'22 I972 3,643,724

SHEET 30F a FIG: 6

INVENTOR VERA/E E. LEE

Allorne METHOD OF INDICATING THE LEVEL OF A MOLTEN FLUID BACKGROUND OF THE INVENTION Heretofore, a steel pourer had to make an experienced guess to determine when to stopthe flow of the molten steel from the teeming ladle at a predetermined level in the hot top of an ingot mold. This predetermined level is known as the pour-down level on top" which predetermined level the steel pourer endeavors to obtain, based on a per-inch requirement in the hot top casing specified on the Ingot Weight Chart followed by the steel pourer for the metallurgically designated height of the ingot to be processed. The teeming ladle is positioned by an overhead traveling crane so that the pouring nozzle, located on the underside of the ladle, is approximately 3 feet above the mouth of the hot top casing. This position of the teeming ladle makes it very difficult for the steel pourer to peer past the bulk of the ladle bottom to the hot top casing, which hot top casing is a further distance from the steel pourer. Due to the limited angle of visibility and the turbulence of the steel being teemed, the steel pourer has no way of knowing when he should shut off the flow of hot metal from the ladle in order to arrive at the predetermined level in the hot top. Therefore, the steel pourer will continue teeming the molten steel until he can see, from where he is standing, the steel rising in the hot top.

The following are some of the defects and disadvantages of this conventional method:

1. a loss of molten steel yield, from overpouring in the mold, which loss cannot be recovered in the primary or rolling mills;

2. a loss of product yield in the primary mills, from underpouring steel in the mold, thereby reducing the yield (due to the top cut or cropping of the ingot) because of insufficient volume of ingot;

3. the unsafe position of the steel pourer when he is in doubt as to when to stop teeming when he shuts off the flow, moves closer, and peers into the mold as well as possible to get some idea whether additional teeming is required; and

4. the incidence of hot-top stickers with overpoured steel, is greater because of the higher hot-top sinkheads resulting from overpoured steel.

Conventional devices of this type are shown in the following patents:

OBJECTS OF THE INVENTION It is the general object of this invention to avoid and overcome the foregoing and other difficulties of and objections to prior art practices by the provision of an improved method for indicating the level ofa molten fluid which:

1. provides a positive means of accurately determining the pour height of the molten steel in the hot top on the ingot mold;

2. materially reduces the loss of product yield resulting from overpouring of an ingot, thereby producing a savings of approximately $22,000.00 per month on various mold sizes based on an average of about 1.97 percent yield improvement;

3. minimizes the man hours and material of the repair work necessary to render hot tops reusable by eliminating hot-top stickers, which hot-top stickers damage the hot-top linings and increase hot-top preparation work;

4. facilitate the work of the steel pourer in determining the pour-down level and reduces the safety hazards involved;

5. gives consistent reliable indication of the pour-down level in the hot top;

6. has no working parts which require maintenance or could experience failure;

7. is versatile and easily formed to suit various hot top sizes;

8. is formed of economical readily available common mill materials; and

9. reduces the time expended by the steel pourer and the difficulties encountered by the steel pourer, thereby affording a less hazardous and improved working condition for the steel pourer.

BRIEF SUMMARY OF THE INVENTION The aforesaid objects of this invention, and other objects which will become apparent as the description proceeds, are achieved by providing an improved method for indicating the level of a molten fluid.

A method of indicating a predetermined level of a molten fluid contained in an ingot-forming member for forming the molten fluid into an ingot when it cools is disclosed. The ingotforming member has a molten fluid receiving end, an inner wall, an outer wall and a top wall bridging the inner wall and the outer wall. The method includes the steps of: (a) providing a support member in loose fitting engagement with the ingotforming member and having an outside support portion adjacent the outer wall, an inside support portion adjacent the inner wall and a bridging support portion adjacent the top wall for connecting the outside support portion and the inside support portion, and (b) mounting a float member on the free end of the inside support portion to extend inwardly from the inner wall at the predetermined level substantially parallel to the level of the fluid line of the molten fluid, The float member has a molten fluid contact volume so that the mean density of the sum of the weights of the support member and the float member per unit of volume of the contact volume is less than the mean density of the molten fluid and so that when the molten fluid engages the float member the support member moves away from the top wall of the ingot-forming member thereby giving a visual signal of the molten fluid reaching the predetermined level. The float member is formed of a material having an ignition temperature lower than the temperature of the molten fluid so that the float member is partially consumed upon contact with the molten fluid thereby decreasing the weight of the indicating device and produces downward flowing gases from the float member against the molten fluid to aid in the elevation of the float member thereby speeding up the visual signal.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS For a better understanding of this invention, reference should be had to the accompanying drawings wherein like numerals of reference indicate similar parts throughout the several views and wherein:

FIG. 1 is a diagrammatic sectional view of an ingot mold and a hot-top casing and the improved molten fluid level indicating device of this invention and showing the molten fluid or steel below the predetermined level within the ingot mold;

FIG. 2 is an isometric view of the improved molten fluid level indicating device shown in FIG. 1;

FIG. 3 is a view similar to FIG. 1 and showing the molten fluid within the hot-top casing at the predetermined level and the support member of the molten fluid level indicating device raised above the hot-top casing to give a visual signal that the molten fluid has attained the desired predetermined level;

FIG. 3A is an enlarged fragmentary view of a portion of FIG. 3 showing the elevation of the float;

FIG. 4 is a fragmentary plan view of an apparatus for forming the support member for the molten fluid level indicating device from an elongated member and showing the forming of the mounting portion of the support member from the solid line position to the dotted line position with the remainder of the support of the elongated member projecting in the dotted line position between the inner support portion forming means and the bridging support portion forming means;

FIG. 5 is a view similar to FIG. 4 and showing the remainder 'of the elongated member formed around the bridging support portion forming means to form a bridging support portion with a second remainder of the elongated member being bent around the other end of the bridging support portion forming means beyond the outer support portion forming means so that when the second remainder is released from the solid line position shown in FIG. 5, the second remainder is aligned in the dotted line position with the outer support portion forming means and becomes the outer support portion;

FIG. 6 is a view similar to FIG. 2 of an alternative embodiment of the molten fluid indicating device and showing a mounting portion on the support member inserted in a formed slot in the float member, a retaining portion on the end of the mounting portion and a fastener extending through the slot to secure the mounting portion in the slot in the float member;

FIG. 7 is a fragmentary enlarged side elevational view of the lower portion of the inside support portion, the mounting por tion and the retaining portion of the support member and showing the float member secured on the mounting portion and retaining portion by means of fasteners; and

FIG. 8 is a view similar to FIG. 7 and showing the float member secured on the bottom of the mounting portion and secured thereon by the retaining portion of the support member by means of fasteners.

Although the principles of this invention are broadly applicable to a molten fluid level indicating device for use with an ingot-forming member for receiving a molten fluid such as steel, copper, glass or the like, this invention is particularly adapted for use in conjunction with an ingot forming member for molten steel and hence it has been so illustrated and will be so described.

DETAILED DESCRIPTION With specific reference to the form of this invention illustrated in the drawings and referring particularly to FIGS. 1-3, an ingot forming member of the type shown in US. Pat. No. 3,027,612 issued to Ivory on Apr. 3, 1962 for receiving a molten fluid 10 (FIGS. 1,3,3A), such as steel or the like, in a cavity 18 (FIGS. 1,2) from the nozzle 12 (FIGS. 1,3) of a ladle (not shown) is indicated generally by the reference numeral 14 (FIGS. 1,2). This ingot mold 14 forms the molten steel 10 into an ingot (not shown) when it cools. In FIGS. 1,3,3A, a hot-top casing 15, similar to the one shown in such US Pat. No. 3,027,612 is mounted on the ingot mold 14 by means of wooden blocks 15a (FIGS. 1,3). The hot-top casing 15 has a molten fluid-receiving end 16 (FIGS. 1,3) adjacent and in registry with the cavity 18 in the ingot mold 14, an inner wall 20 (FIGS. 1,3,3A), an outer wall 22 (FIGS. 1,3) and a top wall 24 (FIGS. 1,3) bridging the inner wall 20 and the outer wall 22. A molten fluid level indicating device 26 of this invention, shown in FIGS. 1,2,3,3A, is employed to give a visual signal when the molten steel 10 reaches a predetermined level B-B, (FIGS. 1,2,3,3A).

INDICATING DEVICE 26 The indicating device 26 has a support member 28 (FIGS 1-3) in loose fitting engagement with the hot top casing 15 and separated from the inner wall 20 and the outer wall 22 of the hot-top casing 15 by a clearance distance d (FIGS. 1,3). The support member 28 (suitably steel strap or the like) has an outside support portion 30 (FIGS. 1-3) adjacent the outer wall 22, an inside support portion 32 (FIGS. l-3, 3A) adjacent the inner wall 20 and a bridging support portion 34 (FIGS. l3) adjacent the top wall 24 for connecting the outside support portion 30 and the inner support portion 32. A float member 36 (FIGS. l-3, 3A) suitably formed of white pine wood or the like, and having dimensions of about 1 inch X 4% inches X 3 inches, is mounted on the free end 38 (FIGS. l-3,3A) of the inner support portion 32 by means of fasteners 40 (FIGS. 13, 3A), such as nails, screws or the like, and extends inwardly, as shown in FIGS. 1-3, 3A, from the inner wall 20 at the predetermined level BB substantially parallel to the level AA (FIGS. 1,3) or fluid line of the molten steel shown in FIG. 1.

This float member 36 has a molten fluid contact volume such that the mean density of the sum of the weights of the steel strap support member 28 and the wooden float member 36 per unit of volume of this contact volume is less than the mean density of the molten steel 10. Thus, when the molten steel 10 engages the float member 36, the support member 28 moves away from the top wall 24 of the hot-top casing 15 a distance D (FIG. 3) thereby giving the operator a visual signal that the molten steel 10 has reached the predetermined level BB shown in FIGS. 1 and 3 and thereby enabling the operator to quickly shut off the flow of molten steel from the nozzle 12 into the molten fluid receiving end 16 of the hot-top casing 15.

It will be understood by those skilled in the art that since the wooden float member 36 is formed from a material having an ignition temperature lower than the temperature of the molten steel (i.e., about 2,900 F.), the float member 36 is partially consumed upon contact with the molten steel 10 (FIG. 3A) thereby reducing the total weight of the support member 28 and the float member 36 so that the indicating device 26 rises more quickly thereby speeding up the visual signal to the operator of the attainment of the predetermined level BB (FIGS. 1,3).

In addition as shown in FIG. 3A downward flowing gases from the float member 36 (indicated by the solid arrows), upward flowing gases from the molten steel 10 (indicated by the dotted line arrows) and splashes 41 of molten metal 10 aid in the elevation of the float member 36.

APPARATUS Referring now to FIGS. 4 and 5, an apparatus 42 for forming from an elongated member 44 (FIG. 4), such as a predetermined length of about 4 feet of steel strap about three-fourths inch X 0.031 gauge or the like, either the support member 28 (FIG. 6) for the indicating device 26 or the support member 28 (FIGS. 13,3A) for the indicating device 26. The apparatus has a frame 46, suitably a flat plate or the like as shown in FIGS. 4 and 5 mounted as by bolts 47 or the like on a table 47a or the like. The apparatus 42 has an inner support portion forming means 48 on one side of the frame 46 for receiving the elongated member 44. This inner support portion forming means 48 is suitably a steel plate or the like upstanding from the frame 46 provided with a plurality of spaced apertures or slots 50 (suitably about 1 inch apart) for receiving one free end of the elongated member 44. This free end of the elongated member 44 is inserted in a selected slot 50 a predetermined distance d (FIGS. 4,5) to form a mounting portion 62 (FIGS. 4,5,6) and the remainder R (FIG. 4) of the elongated member 44 is bent substantially at right angles along the plate 48 from the solid line position (FIG. 4) to the dotted line position (FIG. 4) to form the inner support portion 32 with the second remainder 52 of the elongated member 44 projecting between the other end of the plate 48 and an adjacent end of a bridging support portion forming means 54 (FIGS. 4,5).

If the support member 28 (FIGS. 13,3A) is formed on the apparatus 42, the step of forming the mounting portion 62 is, of course, eliminated.

This bridging support portion forming means 54 comprises a plurality of, for example, three pipes, pegs or the like 56a, 56b, 56c (FIGS. 4,5) upstanding from the frame 46 and contoured to the shape of the bridging portion 34 of the support member 28. The remainder 52 of elongated member is then formed around the pipes 56a, 56b, 560 (FIG. 5) to form the bridging support portion 34 of the support member 28 with a third remainder R (FIG. 5) of the elongated member 44 being bent around the other end or last peg 560 of the bridging support portion forming means 54 beyond an outer support portion forming means 60 (suitably a flat elongated steel plate or the like upstanding from the frame 46 and contoured to the outer support portion 30 of the support member 28) so that when the second remainder R is released from the solid line position shown in FIG. 5 the second remainder R is aligned with the outer support portion forming means 60 (in the dotted line position shown in FIG. 5) and becomes the outer support portion 30 of the support member 28.

ALTERNATIVE EMBODIMENTS It will be understood by those skilled in the art that alternatively as shown in FIG. 6 the indicating device 26 may be modified as shown therein. In FIG. 6, the indicating device 26 has the mounting portion 62 extending substantially at right angles from the free end 38 of the inner support portion 32 of the support member 28 and inserted in a slot 64 in the float member 36. The protruding portion of the mounting portion 62 is then bent at right angles to the mounting portion 62 either upwardly as shown in FIG. 6 or downwardly (not shown) to form a retaining portion 66 of the support member 28. A fastener .68 such as a nail, screw, bolt and nut or the like is inserted across the slot 64 to secure the mounting portion 62 in the slot 64.

In FIG. 7, the mounting portion 62 of the support member 28 is disposed beneath the float 36 and the retaining portion 66 extends upwardly adjacent the right hand end of the float member 36". Suitable fasteners 68", similar to fasteners 68, (FIG. 6) are employed to secure the inner support portion 32, the mounting portion 62 and the retaining portion 66' to the float member 36".

In FIG. 8 the float member 36 is mounted on the bottom of the mounting portion 62 and the retaining portion 66 is bent downwardly along the float member 36 Suitable fasteners, such as nails 68 or the like, secure the mounting portion 62 and the retaining portion 66 to the float member 36*.

It will be understood by those skilled in the art that alternatively the float members 36, 36 36, 36 may be secured to the support member 28 by means of an adhesive similar to Nexus S8007 high-temperature epoxy adhesive. Nexus S8007 is the trade name for such an adhesive manufactured by the assignee of the subject invention.

It is further contemplated that the float members 36, 36, 36 36* may be formed alternatively from the following materials shown in the Table I below.

Table I below lists the densities in pounds/cu. ft. of materials which can be employed in the liquid state as liquids l and in the solid state as float members 36:

Density Material (pounds/cu. ft.)

Mortar, lime, hard I Mortar, natural cement, hard I Mortar, Portland cement, hard I35 Quartz, common. pure I65 Sandstone I5l Silver 655 Slate I75 Steel 490 Tar 62 Timber:

Ash, American. white, dry 38 Cedar, dry 23 Cherry, dry 42 Chestnut, dry 4] Cypress 29 Elm, dry 35 Fir, yellow and red 30 Hemlock, dry Hickory, dry 53 Lignum, Vitac, dry 4I-83 Mahogany, Spanish, dry 53 Mahogany, Honduras, dry 35 Maple, dry 49 Oak, white, dry 50 Pine, white, dry 25 Pine, yellow, short leaf, dry 35 Pine, yellow, long leaf, dry 40 Pine, red, Norway dry 3I Poplar, dry 29 Redwood, California, dry 24 Spruce, dry 25 37 Sycamore, dry

Walnut, black, dry 38 Tin, cast 45) Water, fresh 62 a Water, salt 64 Zinc or Spelter 437% Aluminum l 62 Anthracite, solid 93 Asphalt, top and binder I07 Brass (copper and zinc), cast 504 Brick, pressed I50 Brick, common I 25 Brick, soft I00 Bronze, 5 29 Cement, Portland, packed IOII-I l5 Cement, Portland.

standard for proportions I00 Clay, potters, dry I I9 Coal, bituminous, solid Concrete, cinder I I0 Concrete, broken stone or gravel I45 Concrete, cyclopean I55 Concrete, stone or gravel. reinforced I50 Copper, cast 542 Copper, rolled 548 Flint 162 Glass, common I57 Gneiss, common I70 Gold, cast, pure, or 24 carat [,204 Gold, pure, hammered 1,2 I 7 Granite I70 Gypsum (plaster of paris I42 Ice 58 Iron, cast 450 Iron, wrought, average 480 Lead 7I I Masonry, granite ashlar I65 Masonry, limestone marble ashlar I60 Masonry, sandstone ashlar I40 Masonry, granite, mortar rubble I55 Masonry, limestone, mortar rubble I50 Masonry, sandstone, mortar rubble I30 Masonry, granite, dry, rubble I30 Masonry, limestone, dry rubble I25 Masonry, sandstone, dry rubble Specific gravity is the ratio between the density of a specimen and the density of a standard material, such as pure water at about 4 C. The materials listed in Table II below may be used in the liquid state as liquids l0 and in the solid state as float members 36:

It will also be understood that those of the above-listed materials which are meltable into a molten fluid may be employed as the molten fluid 10.

METHOD It will be understood from the above description of the apparatus 42 and the indicating device 26, 26, 26 and 26 that a novel method for making a molten fluid level indicator for an ingot-forming member, such as the hot top casing 15 or the ingot mold 14, is contemplated. This method (FIGS. 4,5) includes the steps of:

a. forming an inner support portion 32 on the elongated member 44,

b. forming a bridging support portion 34 on the elongated member 44 adjacent the inner support portion 32,

c. forming an outer support portion 30 on the elongated member adjacent the bridging support portion 34, and

d. mounting a float member 36 on the free end of the inner support portion 32.

In addition, the above-described method includes the steps of:

a. mounting the float member 36 by means of a fastener 40 (FIGS. 1-3, 3A) on the support member 28,

b. forming a mounting portion 62 on the support member 28,

c. forming a slot 64 (FIG. 6) in the float member 36 and inserting the mounting portion 62 in the slot 64, and

d. securing the mounting portion 62 in the slot 64 by means ofa fastener 68 (FIG. 6) or the like.

SUMMARY OF THE ACHIEVEMENTS OF THE OBJECTS OF THE INVENTION It will be recognized by those skilled in the art that the objects of this invention have been achieved by providing an improved molten fluid level indicating device 26 (FIGS. L3), 26 (FIG. 6), 26" (FIG. 7), and 26 (FIG. 8). This invention provides a positive means for accurately determining the pour height B-B (FIGS. 1,3,3A) of the molten steel 10 in the hottop casing or in the ingot mold l4; materially reduces the loss of production yield of steel resulting from the overpouring of an ingot thereby producing a savings of approximately $22,000 a month based on various sizes ofingot molds 14 and on an average of about l.97 percent yield improvement; minimizes the man hours and materials involved in repair work necessary to render the hot-top casings l5 reusable by eliminating hot-top stickers (not shown) which hot-top stickers damage the linings of the hot-top casings 15 and increase the preparation work for such hot-top casings 15; facilitates the work of the operator in determining the pourdown level BB (FIGS. 1,3,3A) and reduces the safety hazards to the operator; gives a consistent and reliable indication of the pour-down level BB (FIGS. 1,3,3A) in the hottop casing 15 or in the ingot mold 14; has no working parts which require maintenance or will experience failure; is versatile and easily formed to suit the various sizes of the hot-top casings 15 or ingot molds 14; is formed of economical and readily available common mill materials; and reduces the time expended by the operator or steel pourer and the difficulties encountered by him thereby affording a less hazardous and improved working condition for such operator.

While in accordance with the patent statutes preferred and alternative embodiments of this invention have been illustrated and described in detail, it is to be particularly understood that the invention is not limited thereto or thereby.

I claim:

1. A method of indicating a predetermined level of a molten fluid contained in an ingot-forming member for forming said molten fluid into an ingot when it cools, said ingot-forming member having a molten fluid receiving end, an inner wall, an outer wall and a top wall bridging said inner wall and said outer wall, said method including the steps of:

a. providing a support member in loose fitting engagement with said ingot-forming member and having an outside support portion adjacent said outer wall, an inside support portion adjacent said inner wall and a bridging support portion adjacent said top wall for connecting said outside support portion and said inside support portion,

. b. mounting a float member on the free end of said inside support portion to extend inwardly from said inner wall at said predetermined level substantially parallel to the level ofthe fluid line of said molten fluid, 1. said float member having a molten fluid contact volume so that the mean density of the sum of the weights of said support member and said float member per unit of volume of said contact volume is less than the mean density of said molten fluid and so that when said molten fluid engages said float member said support member moves away from the top wall of said ingot-forming member thereby giving a visual signal of said molten fluid reaching said predetermined level,

2. said float member being formed of a material having an ignition temperature lower than the temperature of said molten fluid so that said float member is partially consumed upon contact with said molten fluid thereby decreasing the weight of said indicating device and produces downward flowing gases from said float member against said molten fluid to aid in the elevation of said float member thereby speeding up said visual signal.

2. The method recited in claim 1 including the step of mounting said float member on said free end of said inside support portion by means of a fastener.

3. The method recited in claim 1 wherein said molten fluid is molten steel.

4. The method recited in claim 1 wherein said float member is wood.

uurvu 

1. A method of indicating a predetermined level of a molten fluid contained in an ingot-forming member for forming said molten fluid into an ingot when it cools, said ingot-forming member having a molten fluid receiving end, an inner wall, an outer wall and a top wall bridging said inner wall and said outer wall, said method including the steps of: a. providing a support member in loose fitting engagement with said ingot-forming member and having an outside support portion adjacent said outer wall, an inside support portion adjacent said inner wall and a bridging support portion adjacent said top wall for connecting said outside support portion and said inside support portion, b. mounting a float member on the free end of said inside support portion to extend inwardly from said inner wall at said predetermined level substantially parallel to the level of the fluid line of said molten fluid,
 1. said float member having a molten fluid contact volume so that the mean density of the sum of the weights of said support member and said float member per unit of volume of said contact volume is less than the mean density of said molten fluid and so that when said molten fluid engages said float member said support member moves away from the top wall of said ingot-forming member thereby giving a visual signal of said molten fluid reaching said predetermined level,
 2. said float member being formed of a material having an ignition temperature lower than the temperature of said molten fluid so that said float member is partially consumed upon contact with said molten fluid thereby decreasing the weight of said indicating device and produces downward flowing gasEs from said float member against said molten fluid to aid in the elevation of said float member thereby speeding up said visual signal.
 2. said float member being formed of a material having an ignition temperature lower than the temperature of said molten fluid so that said float member is partially consumed upon contact with said molten fluid thereby decreasing the weight of said indicating device and produces downward flowing gasEs from said float member against said molten fluid to aid in the elevation of said float member thereby speeding up said visual signal.
 2. The method recited in claim 1 including the step of mounting said float member on said free end of said inside support portion by means of a fastener.
 3. The method recited in claim 1 wherein said molten fluid is molten steel.
 4. The method recited in claim 1 wherein said float member is wood. 